This morning on my way to work my 2002 A4 1.8t (63k) started to
hesitate under acceleration (manual trans) and then the CEL came on
and started flashing about once a second. The power dropped and I
could hear the exhaust sort of pop a little, like it might be firing
only 3 cylinders (?). It started at about the point where the car
usually hits its operating temp, if that makes a difference. I use
Shell gas primarily and just had the timing belt replaced and the rear
seal replaced. I'm the second owner and I know the coil pack was
replaced somewhere in the 25k region. When I parked the car there was
a definite wet sort of cooking smell, not burning, coming from the
exhaust. Didnt smell like coolant. And I could definitely hear
something through the exhaust that sounded like a rhythmic muffled
clank. Right now she's parked in the paring lot and I am afraid to
drive it too much because I know from experience that these problems
can get more expensive the more you drive on them. I bought a new set
of coils when I got the car thinking that I'd need to replace them,
but I didnt since the service tech @ the dealer told me to wait until
it started running like crap... is this what he meant? How do I
determine if its the coils? Or a knock sensor? or an O2 sensor?
ANY advice would be greatly appreciated.
Thanks
Mike

 

<flailmaster@gmail.com> wrote in message
news:119ce294-c9d8-4e8f-b4c5-ad945f11bd43@u10g2000vbd.googlegroups.com...
> This morning on my way to work my 2002 A4 1.8t (63k) started to
> hesitate under acceleration (manual trans) and then the CEL came on
> and started flashing about once a second. The power dropped and I
> could hear the exhaust sort of pop a little, like it might be firing
> only 3 cylinders (?). It started at about the point where the car
> usually hits its operating temp, if that makes a difference. I use
> Shell gas primarily and just had the timing belt replaced and the rear
> seal replaced. I'm the second owner and I know the coil pack was
> replaced somewhere in the 25k region. When I parked the car there was
> a definite wet sort of cooking smell, not burning, coming from the
> exhaust. Didnt smell like coolant. And I could definitely hear
> something through the exhaust that sounded like a rhythmic muffled
> clank. Right now she's parked in the paring lot and I am afraid to
> drive it too much because I know from experience that these problems
> can get more expensive the more you drive on them. I bought a new set
> of coils when I got the car thinking that I'd need to replace them,
> but I didnt since the service tech @ the dealer told me to wait until
> it started running like crap... is this what he meant? How do I
> determine if its the coils? Or a knock sensor? or an O2 sensor?
> ANY advice would be greatly appreciated.
> Thanks
> Mike

Hi, when it goes into limp home mode it feels like it's firing on 3
cylinders, coil packs have a different way of showing they are faulty,
believe it or not my first coil pack went 1 month ago at 200,000 <2002 1.8t
q>, I was driving along normally and then all of sudden the car started
missing when you pulled away, after a day of this missing it then got so bad
I could hardly drive it, so thought best to change 1

You need a VAG-com to read the codes, other than that go to a
dealer/specialist and ask them to read them for you.

Try changing all 4 coil packs, disconnect the battery leave it off for 5
mins then put it back on, this will usually clear the CEL don't forget the
stereo code if you have it.